Monthly Archives: January 2013

Condom Trace Evidence: A New Factor in Sexual Assault Investigations

By Robert D. Blackledge, M.S.
Mr. Blackledge is senior chemist at the Naval Criminal Investigative Service Regional Forensic Laboratory in San Diego, California.

This Article Originally Appeared in the FBI Law Enforcement Bulletin, May 1996.

(Offenders are changing the nature of sexual assault investigations by wearing condoms.)
In an age filled with potentially fatal sexually transmitted diseases, more and more individuals practice safe sex. Even perpetrators of sex crimes have begun to wear condoms.1 It is not likely that a fear of disease prompts this behavior. Rather, just as a burglar dons gloves to avoid leaving fingerprints, sexual offenders now wear condoms to avoid depositing seminal fluids. Continue reading

Caught on Tape

Using Criminals’ Videos Against Them

By Edward F. Davis, M.S., and Anthony J. Pinzotto, Ph.D.

This article originally appeared in the FBI Law Enforcement Bulletin, November, 1998.

In Sparta, Michigan, a 16-year-old high school dropout with a criminal record bludgeons a man to death, then cuts off his head. At home, the youth repeatedly slashed the severed head with a butcher knife, and removes the brain. Detectives recover the head wrapped in plastic outside the youth’s home. [1]

In Fort Lauderdale, Florida, five teenagers vandalize and burglarize eight homes and a school. During their escapades, they blow up a live sea trout in a microwave and get a dog high on marijuana. [2] Continue reading

Burglary Investigations

By Daryl W. Clemens

Burglary defined

Burglary is sometimes also known as Home Invasion, or Breaking and Entering. The unlawful entry into the premises of another with intent to commit a felony (usually larceny) therein.

Introduction

Burglaries represent one of the more common crimes to which patrol officers respond. Someone has returned home from an evening out and found the doors open and their property missing. The police are called, and an investigation is begun. Continue reading

Black Powder Processing

By Pat A. Wertheim

This article originally appeared in “Minutiae”, The Lightning Powder Co. Newsletter, No. 42, May-June 1997, p. 6.

Although old-fashioned black powder is the workhorse of fingerprint development
techniques for crime scene use and is also an important method in the laboratory,
maximizing the effectiveness of powder requires far more sophistication than
simply dipping a brush into the jar of powder and painting it onto a surface.

More control can be exercised over black powder by working out of a shallow
dish. The perfect disposable dish can be made by cutting or tearing a blank
inked fingerprint card from any edge into the center of the card. Overlap
the two edges of the cut by about an inch (two or three centimeters) and
tape the card back together to make the dish. A large laboratory weighing
dish may be used, or any other shallow dish or bowl. Place one-half to one
teaspoon of powder (approximately one millilitre) into the dish. Continue reading

Bite Mark Analysis

Written by Katherine Steck-Flynn

Ted Bundy was a killer. Not only was he a killer but he was a serial killer. He rampaged through a large part of the United States killing and brutalizing women from 1974 until his eventually capture in 1978(Ramsland, 2004). He was captured twice and managed to escape twice. Under stress from life as a fugitive he made the fatal mistake which would lead to his conviction and eventual execution.

Ted Bundy bludgeoned, raped and tortured more than 30 women. Some estimates are closer to forty. Yet he did not fit the profile of a killer. He was intelligent and some say handsome. He seemed to have a future as a lawyer. He killed most of his victims without leaving any traceable evidence. In some cases the bodies were not found until years later. In most cases he left no fingerprints or other traceable evidence. DNA was recovered but could not be matched conclusively to Ted Bundy( Ramsland, 2004). Continue reading

Fingerprints: The Origins of Crime Detection and the Murder Case that Launched Forensic Science

Thoroughly researched and engagingly written, this book is sure to appeal to people in the fingerprint profession, and to those who love history. The book centers around “The Shocking Tragedy at Deptford”, the murder case which became the first in the United Kingdom which was solved through the use of fingerprint evidence. (There were earlier cases in other countries, and an account of one from Argentina is also included in the text).

Continue reading

Bad Science

by D. H. Garrison, Jr.
Forensic Services Unit
Grand Rapids Police Department
Grand Rapids, Michigan

This Article Originally Appeared in the MAFS Newsletter, October 1991.

Forensic science is the product of an uneasy and unholy mating of Science,
the objective seeker of truth and knowledge, and Forensics, the argumentative
persuader of courtroom advocacy. It is not called Justice Science, Law Science,
or Truth Science, as many of us would like to imagine. We are a bastard child,
an orphan, but still the subject of an intense child custody battle between
our estranged parents, the truth seeker and the advocate. The tug-of-war
goes on daily for our loyalties and confidences, each side offering candy
and warm hugs. These separated parents have visitation rights. Sometimes
they take our brothers and sisters away. Sometimes they don’t come back. Continue reading

Arson Investigation

Written by Katherine Steck-Flynn

The Fire

Arson investigation starts with the fire itself. To create and sustain a fire three factors must be present. The three factors are known as the fire triangle (Peige ed., 1977). The fire triangle consists of oxygen, a fuel source, and heat. In most cases the percentage of oxygen concentration must be above 16% (Peige, ed., 1977). The fuel may be any flammable substance. The heat source needs only to match the ignition temperature of the fuel.

In a fire involving arson the arsonist will have tampered with one or more of the factors in the fire triangle. The arsonist may increase the fuel load by introducing flammable material or by adding accelerants such as kerosene, gasoline or alcohol (French, 1979) The arsonist may increase the oxygen content of a structure by opening windows or punching holes in ceilings and walls (French, 1979) Fire will follow the highest concentration of oxygen to its source. By ventilating a structure at the top and starting a fire at the bottom of the structure an arsonist can cause the fire to race upward through the structure. The fire will rapidly involve the whole structure rather than be confined to one room. Continue reading

Hidden Evidence: Latent Prints on Human Skin

By Ivan Ross Futrell
Mr. Futrell is a supervisory fingerprint specialist in the Latent Fingerprint
Section of the FBI Laboratory in Washington, D.C.

This Article Originally Appeared in the FBI Law Enforcement Bulletin, April 1996.

(Recent research proves that identifiable prints can be obtained from the
skin of homicide victims under real field conditions, not just in the
laboratory.)

Whether to stop them from fleeing, immobilize them, or dispose of them, murderers
often grab their victims. What homicide detective has not wished for the
ability to develop identifiable fingerprints of a suspect from the skin of
a dead body? Crucial fingerprint evidence linking the perpetrator to the
victim must be right there, but, until recently, attempts to retrieve those
prints rarely met with success. Continue reading